ok keep getting a rich code on my civic. As far as the car running it runs great i just keep getting rich codes and it does run rich at idle. I replaced both o2 sensors but i think i got the wrong one for the downstream sensor. So here are the specs on my car it is a 98 civic DX with a d16y8 swap. now car still has the DX Ecu in it. I have heard that the upstream and downstream o2 sensors are the same but i bought 2 different ones.. If anyone has the part numbers i need for the right o2 sensors that would be cool.

 

I believe both o2 sensors are the same. The Denso o2 sensor which is what they came out of the factory with is 234-4099

 

Both the o2 sensors are indeed the same as I have recently replaced both of mine. Where did you get the o2's at? I would return them and get some from Autozone if possible as they can get you exactly what you need without any guessing. That's what I'd do anyway.

What are you driving btw, coupe or hatch?

 

i got them off rockauto. i think i got one right but the other is wrong so hopefully i only need to order one. but i drive a coupe. i have a few pix up on my profile i think.